(a) Technical Field
The present disclosure relates to an apparatus for preventing over-cooling of a fuel cell, and more specifically, to an apparatus for preventing over-cooling of a fuel cell, in which a flow amount of cooling fluid participating in cooling of end cells is reduced through shape modifications of end plates, thereby preventing over-cooling of the end cell in order to avoid flooding of stacks of fuel cells.
(b) Background Art
Generally, a stack of a fuel cell for a vehicle is configured with a plurality of cells being connected in series wherein air, fuel (hydrogen) and cooling fluid are supplied and discharged at an end of the stack. As shown in FIG. 1, in the cell (power generating cell) an anode separating plate 1a and a cathode separating plate 1b are arranged at both sides of an Membrane Electrode Assembly (MEA) (power generating body) and Gas Diffusion Layers (GDLs) are bonded thereat. Additionally, a stack is formed with each unit cell being repeatedly stacked. Additionally, a flow channel 4 of cooling fluid, which is communicated with a cooling fluid manifold 3, is disposed at an interface between two adjacent cells. That is, the interface is disposed between the anode separating plate 1a and the cathode separating plate 1b, and thus, based on the power generating body MEA, about half of each plate thereof is effectively a cooling surface.
However, in case of an end cell facing an end plate 20, since the end cell 2 is disposed at an outermost region of the fuel cell, the cooling fluid for cooling the end cell is only cooled on one side, unlike other cells in the system which are cooled on both sides. As a result, this can cause a flooding phenomenon on a reaction surface of the end cell due to an excessive cooling of the end cell in comparison to the general power generating cells, and as a result the end cells become more deteriorated, compared to the general cells, as time passes.
Additionally, an end cell faces an end plate, additional heat is lost due to heat conduction into the air, even further adding to the problem of deterioration and flooding.
As a solution to this problem, a foaming structure has been added to the fuel cell system, this foaming structure is additionally provided in the vicinity of an inlet/outlet manifold of the cooling fluid in a separating plate. However, these foaming structures require piercing molds among molds for the separating plates used in a general cell and an end cell has to be prepared with two different specifications, and thus the production processes has to be performed separately thus making the manufacturing process more costly.
The invention disclosed in this background of the invention section is only for enhancement of understanding of the background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.